Eating potatoes is not only good for bowel
health, but also for the whole immune system, especially when they come in the
form of a potato salad or eaten cold. In a study on an animal model, researchers
in Spain found that pigs fed large {{U}} {{U}} 1 {{/U}} {{/U}}of
raw potato starch (RPS) not only had a healthier bowel, but also decreased
levels of white blood cells, {{U}} {{U}} 2 {{/U}} {{/U}}as
leucocytes and lymphocytes in their blood. White blood cells are produced as a
{{U}} {{U}} 3 {{/U}} {{/U}}of inflammation or disease, generally
when the body is challenged. The general down-regulation of
leucocytes observed by the Spanish researchers suggests an overall beneficial
effect, a generally more {{U}} {{U}} 4 {{/U}} {{/U}}body. The
reduction in leucocyte levels was about 15 percent. Lower lymphocyte levels are
also indicative of {{U}} {{U}} 5 {{/U}} {{/U}}levels of
inflammation, but the observed reduction in both lymphocyte density {{U}}
{{U}} 6 {{/U}} {{/U}}lymphocyte apoptosis is surprising.
In {{U}} {{U}} 7 {{/U}} {{/U}}was the longest study of
its kind, pigs were fed RPS over 14 weeks to {{U}} {{U}} 8
{{/U}} {{/U}}the effect of starch on bowel health. "The use of raw potato
starch in this experiment is {{U}} {{U}} 9 {{/U}} {{/U}}to
simulate the effects of a diet high in resistant starch," said study leader Jose
Francisco Perez at the Universitat Autonoma de Barcelona, Spain.
Humans do not eat {{U}} {{U}} 10 {{/U}} {{/U}}potatoes,
but they do eat a lot of foods that contain resistant starch, such as cold
boiled potatoes, legumes, grains, green bananas, pasta and cereals. About 10
percent of the starch eaten by human is resistant starch—starch that is not
{{U}} {{U}} 11 {{/U}} {{/U}}in the small intestine and so is
shunted into the large intestine where it ferments. Starch consumption is
thought to reduce the {{U}} {{U}} 12 {{/U}} {{/U}}of large bowel
cancer and may also have an effect on irritable bowel syndrome (IBS).
Immunology expert Lena Ohman's team {{U}} {{U}} 13
{{/U}} {{/U}}found that the overall lymphocyte levels do not vary for IBS
patients, but that lymphocytes are transferred from the peripheral blood to the
gut, which support the hypothesis of IBS being {{U}} {{U}} 14
{{/U}} {{/U}}least partially an inflammatory disorder. She says the decrease
in lymphocytes observed by the Spanish is therefore interesting, and a diet of
resistant starch may be worth {{U}} {{U}} 15 {{/U}} {{/U}}in IBS
patients. Ohman is currently at the Department of Internal Medicine, Goteborg
University, Sweden. The study is published in the Journal Chemistry and
Industry, the magazine of the SCI.